Redox-induced aggregation and dissolution of actinide nanoparticle

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H04247
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: KITATSUJI Yoshihiro 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 原子力基礎工学研究センター, 研究主幹 (30354898)
• Research Collaborator: Watanabe Masayuki ; Otobe Haruyoshi ; Ouchi Kazuki
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: アクチノイド / コロイド / 電解析出 / 水晶振動子マイクロバランス / 還元 / インピーダンス測定

Outline of Final Research Achievements

The mechanism of the complex reaction combining the two reaction of reduction and aggregation of actinide in solution was elucidated by electrochemical analysis. It has been observed that the reduction rate of uranium(V) ion increases when the colloid of a tetravalent uranium formed by reduction precipitate is present. It was clarified that this catalytic effect can be observed also when zirconium tetravalent hydroxide colloids coexist in addition to uranium. It was also clarified that there is a clear difference in the electrolytic deposition behavior between uranium and neptunium, and that this difference is due to the electrochemical characteristics of the deposited chemical species.

Free Research Field

アクチノイド溶液化学

Academic Significance and Societal Importance of the Research Achievements

福島第一原子力発電所の廃炉や放射性廃棄物処分時の環境水中でのウラン等のアクチノイドイオンの挙動予測は、安全評価上重要である。本研究では、原子価変化と凝集反応の二つの反応が組み合わさった新しい反応過程を見出し、その生成化学種を明らかにできた。今後の環境中での挙動予測において、新しい反応モデルの提案につながる成果である。